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Molecular Psychiatry Aug 2021Depression and cardiovascular disease (ischemic heart disease and stroke) are associated in a bidirectional manner. Their relatively high heritability has led to the...
Depression and cardiovascular disease (ischemic heart disease and stroke) are associated in a bidirectional manner. Their relatively high heritability has led to the hypothesis that this co-occurrence is related to shared familial and genetic factors; this study aims to test this hypothesis. We included 23,498 monozygotic and 39,540 same-sex dizygotic twins from the Danish Twin Registry followed from January 1977 until December 2011 in nationwide Danish registries. We used survival analyses accounting for censoring and competing risk of death to estimate cumulative incidence, casewise concordance, relative recurrence risk, and heritability of the co-occurrence of depression and cardiovascular disease by age using monozygotic and same-sex dizygotic twin pairs. The casewise concordance of ischemic heart disease or stroke in twins whose co-twin was diagnosed with depression was at all ages similar for the monozygotic and dizygotic twin pairs and to the cumulative incidence of ischemic heart disease or stroke, respectively, in the entire twin population. A similar pattern was seen in analyses of depression risk given the co-twin being diagnosed with ischemic heart disease or stroke. Relative recurrence risk and heritability estimates were also of modest size and with confidence intervals including unity. Results were similar after stratification by gender as well as when redefining depression to include the use of antidepressant medication from 1995. Our findings do not support that co-occurrence between depression and cardiovascular disease is explainable by shared genetic factors, nor did we find strong evidence of a familial effect.
Topics: Cardiovascular Diseases; Cohort Studies; Denmark; Depression; Diseases in Twins; Genetic Predisposition to Disease; Humans; Registries; Twins, Dizygotic; Twins, Monozygotic
PubMed: 33219357
DOI: 10.1038/s41380-020-00954-6 -
Cancer Epidemiology, Biomarkers &... Sep 2022The time during which there is an increased risk of death for cancer survivors was evaluated in a large twin study, which allows for matching on shared components such...
BACKGROUND
The time during which there is an increased risk of death for cancer survivors was evaluated in a large twin study, which allows for matching on shared components such as age, genes, and socioeconomic factors in childhood.
METHODS
By use of data from Danish registers, time to death from initial cancer was studied prospectively in twins in two different settings. The twins were diagnosed with at least one cancer in the period 1943 to 2011. Setting I included 5,680 same-sex twin pairs aged 6 and over, while Setting II included 3,218 twin individuals from age 70 and over. The study provides comparisons within twin pairs and across birth cohorts, age at diagnoses, and time at diagnosis.
RESULTS
In 2001 to 2011, the 5-year mortality risk for a twin surviving cancer after the age of 70 was twofold that of the co-twin, regardless of sex and zygosity, and it was 1.5-fold if the twin survived the initial 9 months. After 5 to 6 years, the mortality risk corresponded to that of the co-twin. In previous decades, the excess hazard risk was considerably higher for both older and younger cohorts. There were no indications of change in relative survival across old birth cohorts.
CONCLUSIONS
This large twin study suggested that for a cancer-treatment survivor diagnosed at age 70 or later, the additional mortality risk was largely absent 5 years later, by which time the survival relative to the co-twin was 60%.
IMPACT
Elevated mortality risk after cancer is offset after 5 to 6 years.
Topics: Aged; Cohort Studies; Humans; Neoplasms; Socioeconomic Factors; Survivors; Twins; Twins, Dizygotic; Twins, Monozygotic
PubMed: 35820201
DOI: 10.1158/1055-9965.EPI-22-0244 -
The Australian & New Zealand Journal of... Oct 2022The extent to which maternal transmission of primary dysmenorrhoea is genetically determined in adolescents and young women has yet to be determined. We aimed to assess...
AIMS
The extent to which maternal transmission of primary dysmenorrhoea is genetically determined in adolescents and young women has yet to be determined. We aimed to assess heritability and associations relevant to primary pain syndromes using a twin family study.
METHODS
Participants were young menstruating female twins, and their oldest sisters and mothers, whose families were registered with Twins Research Australia and previously participated in a twin family study of primary paediatric pain disorders. Questionnaire packs were mailed, assessing current maximum and average menstrual pain intensity, current pain interference with activities and retrospective dysmenorrhea secondary symptoms.
RESULTS
The sample comprised 206 twin individuals (57 monozygous (MZ) and 46 dizygous (DZ) pairs) aged 10-22 years, eldest siblings (n = 38) aged 13-28 years and mothers (n = 101) aged 32-61 years. The estimated regression coefficient of the relationship between mother-daughter and twin-sibling dyads indicated significant associations for the measures of dysmenorrhea and supported heritability. Adjusted for age, the within twin-pair correlation for MZ twins was generally more than twice that of DZ twins. Heritability estimates were maximal pain intensity 0.67 (P = 3.8 × 10 ), average pain intensity 0.63 (P = 3.7 × 10 ), pain interference 0.57 (P = 1.8 × 10 ) and retrospective symptoms 0.57 (P = 1.8 × 10 ). Twin individuals with a lifetime (three-month) history of iron deficiency and those with painless restless legs syndrome (RLS) were significantly more likely to have more intense pain associated with menstruation.
CONCLUSION
Primary dysmenorrhea in adolescents and young women was shown to be relatively strongly genetically influenced and associated especially with a history of iron deficiency and painless RLS which have potential therapeutic implications.
Topics: Adolescent; Child; Dysmenorrhea; Female; Humans; Mothers; Retrospective Studies; Twins, Dizygotic; Twins, Monozygotic
PubMed: 35754341
DOI: 10.1111/ajo.13560 -
Cerebral Cortex (New York, N.Y. : 1991) Jan 2021To understand the origins of interhemispheric differences and commonalities/coupling in human brain wiring, it is crucial to determine how homologous interregional...
To understand the origins of interhemispheric differences and commonalities/coupling in human brain wiring, it is crucial to determine how homologous interregional connectivities of the left and right hemispheres are genetically determined and related. To address this, in the present study, we analyzed human twin and pedigree samples with high-quality diffusion magnetic resonance imaging tractography and estimated the heritability and genetic correlation of homologous left and right white matter (WM) connections. The results showed that the heritability of WM connectivity was similar and coupled between the 2 hemispheres and that the degree of overlap in genetic factors underlying homologous WM connectivity (i.e., interhemispheric genetic correlation) varied substantially across the human brain: from complete overlap to complete nonoverlap. Particularly, the heritability was significantly stronger and the chance of interhemispheric complete overlap in genetic factors was higher in subcortical WM connections than in cortical WM connections. In addition, the heritability and interhemispheric genetic correlations were stronger for long-range connections than for short-range connections. These findings highlight the determinants of the genetics underlying WM connectivity and its interhemispheric relationships, and provide insight into genetic basis of WM connectivity asymmetries in both healthy and disease states.
Topics: Adult; Diffusion Magnetic Resonance Imaging; Diffusion Tensor Imaging; Female; Functional Laterality; Humans; Male; Neural Pathways; Pedigree; Twins, Dizygotic; Twins, Monozygotic; White Matter; Young Adult
PubMed: 32794570
DOI: 10.1093/cercor/bhaa207 -
Orthodontics & Craniofacial Research May 2020The aims of this longitudinal analysis of untreated monozygotic and dizygotic twins were to investigate vertical changes of the craniofacial structures during growth, to...
OBJECTIVE
The aims of this longitudinal analysis of untreated monozygotic and dizygotic twins were to investigate vertical changes of the craniofacial structures during growth, to determine the concordance between genetically twins and to assess the genetic component for the various aspects of vertical growth.
SETTINGS AND SAMPLE POPULATION
The sample consisted of 34 pairs of untreated monozygotic twins (23 male, 11 female) and 30 untreated dizygotic siblings of multiple birth (8 male, 8 female and 14 mixed) from the Forsyth Moorrees Twin Study (1959-1975); lateral cephalograms taken from 6 to 18 years of age were analysed at 3-year intervals.
MATERIALS AND METHODS
Cephalograms were traced, and longitudinal changes between twins in six angular and proportional vertical cephalometric variables (SN-NL, ML-NL, SN-ML, y-axis, PFH/AFH and LAFH/AFH) were analysed with intraclass correlation coefficients and linear regression modelling.
RESULTS
The concordance between monozygotic/dizygotic twins at 18 years of age was moderate to high with intraclass correlation coefficient values between 0.51 and 0.66. Additionally, sex differences in concordance at 18 years of age were found for three variables. High heritability (66%-79%) was observed for 5 of the 6 variables (LAFH/AFH, ML-NL, y-axis, SN-ML, PFH/AFH), while SN-NL showed limited heritability (34%).
CONCLUSIONS
Although monozygotic/dizygotic twins share at least part of their genetic material, differences in the vertical dimension were found. This supports the complex developmental mechanism of the human face and the varying influence of genetic and environmental factors.
Topics: Adolescent; Cephalometry; Child; Cohort Studies; Female; Humans; Longitudinal Studies; Male; Twins, Dizygotic; Twins, Monozygotic
PubMed: 31746097
DOI: 10.1111/ocr.12358 -
Archives of Disease in Childhood Sep 2020To assess evidence supporting the view that 'low fibre childhood constipation'.
OBJECTIVES
To assess evidence supporting the view that 'low fibre childhood constipation'.
DESIGN
Triangulation integrated three approaches: a systematic review NICE guideline CG99 examining effectiveness of increasing fibre; a cohort study, Avon Longitudinal Study of Parents and Children (ALSPAC), to assess if constipation (or hard stools) can precede fibre intake at weaning; and a literature search for twin studies to calculate heredity.
SETTING
CG99 examined the literature regarding the effectiveness of increasing fibre. ALSPAC asked parents about: hard stools at 4 weeks, 6 months and 2.5 years and constipation at age 4-10 years, as well as fibre intake at 2 years. Twin studies and data from ALSPAC were pooled to calculate concordance of constipation comparing monozygotic and dizygous twin pairs.
PARTICIPANTS
CG99 reported six randomised controlled trials (RCTs). ALSPAC hard stool data from 6796 children at 4 weeks, 9828 at 6 months and 9452 at 2.5 years plus constipation data on 8401 at 4-10 years were compared with fibre intake at 2 years. Twin studies had 338 and 93 twin pairs and ALSPAC added a further 45.
RESULTS
Increasing fibre did not effectively treat constipation. Hard stools at 4 weeks predated fibre and at 6 months predicted lower fibre intake at 2 years (p=0.003). Heredity explained 59% of constipation.
CONCLUSIONS
RCTs indicate that increasing fibre is not an effective treatment for constipation in children. Hard stools can precede and predict later fibre intake. Genetic inheritance explains most childhood constipation. Extended treatment with stool softeners may improve fibre intake and limit long-term damaging sequelae of constipation.
Topics: Adolescent; Child; Child, Preschool; Constipation; Dietary Fiber; Diseases in Twins; Female; Genetic Predisposition to Disease; Humans; Male; Surveys and Questionnaires; Twins, Dizygotic; Twins, Monozygotic
PubMed: 32156695
DOI: 10.1136/archdischild-2019-318082 -
Nutrients Nov 2022This study investigated the contribution of genetic and environmental factors to cardiometabolic diseases (CMDs) by comparing disease concordance in monozygotic and...
Comparison of the Concordance of Cardiometabolic Diseases and Physical and Laboratory Examination Findings between Monozygotic and Dizygotic Korean Adult Twins: A Cross-Sectional Study Using KoGES HTS Data.
This study investigated the contribution of genetic and environmental factors to cardiometabolic diseases (CMDs) by comparing disease concordance in monozygotic and dizygotic twins. This cross-sectional study analyzed 1294 (1040 monozygotic and 254 dizygotic) twin pairs (>20 years) based on the Korean Genome and Epidemiology Study data (2005−2014). The odds ratios of disease concordance were calculated using binomial and multinomial logistic regression models. The occurrence of CMDs (hypertension, hyperlipidemia, type 2 diabetes, cerebral stroke, transient ischemic attack, and ischemic heart disease) and related physical and laboratory levels did not differ between the monozygotic and dizygotic twin groups. The odds for concordance of the presence/absence of CMDs and the likelihood of incident CMD within monozygotic twins were comparable to that of dizygotic twins. The absolute differences in hemoglobin A1c, insulin, low- and high-density lipoprotein cholesterol, total cholesterol, triglycerides, and systolic blood pressure were lower in monozygotic twins than in dizygotic twins. Absolute differences in fasting glucose and diastolic blood pressure did not differ between groups. Although baseline levels of several laboratory parameters related to CMD showed a strong likelihood of heritability in monozygotic twins, CMD phenotype appears to be largely affected by environmental factors.
Topics: Humans; Twins, Dizygotic; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Ischemic Attack, Transient; Cholesterol, HDL; Republic of Korea
PubMed: 36432523
DOI: 10.3390/nu14224834 -
The Journal of Clinical Endocrinology... Feb 2020Inter-individual differences in cortisol production and metabolism emerge with age and may be explained by genetic factors.
CONTEXT
Inter-individual differences in cortisol production and metabolism emerge with age and may be explained by genetic factors.
OBJECTIVE
To estimate the relative contributions of genetic and environmental factors to inter-individual differences in cortisol production and metabolism throughout adolescence.
DESIGN
Prospective follow-up study of twins.
SETTING
Nationwide register.
PARTICIPANTS
218 mono- and dizygotic twins (N = 109 pairs) born between 1995 amd 1996, recruited from the Netherlands Twin Register. Cortisol metabolites were determined in 213, 169, and 160 urine samples at the ages of 9, 12, and 17, respectively.
MAIN OUTCOME MEASURES
The total contribution of genetic factors (broad-sense heritability) and shared and unshared environmental influences to inter-individual differences in cortisol production and activities of 5α-reductase, 5β-reductase, and 11β-hydroxysteroid dehydrogenases and cytochrome P450 3A4.
RESULTS
For cortisol production rate at the ages of 9, 12, and 17, broad-sense heritability was estimated as 42%, 30%, and 0%, respectively, and the remainder of the variance was explained by unshared environmental factors. For cortisol metabolism indices, the following heritability was observed: for the A-ring reductases (5α-and 5β-reductases), broad-sense heritability increased with age (to >50%), while for the other indices (renal 11β-HSD2, global 11β-HSD, and CYP3A4), the contribution of genetic factors was highest (68%, 18%, and 67%, respectively) at age 12.
CONCLUSIONS
The contribution of genetic factors to inter-individual differences in cortisol production decreased between 12 and 17y, indicative of a predominant role of individual circumstances. For cortisol metabolism, distinct patterns of genetic and environmental influences were observed, with heritability that either increased with age or peaked at age 12y.
Topics: 11-beta-Hydroxysteroid Dehydrogenases; 3-Oxo-5-alpha-Steroid 4-Dehydrogenase; Adolescent; Biosynthetic Pathways; Child; Cytochrome P-450 CYP3A; Female; Follow-Up Studies; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Male; Netherlands; Oxidoreductases; Prospective Studies; Quantitative Trait, Heritable; Registries; Twins, Dizygotic
PubMed: 31608377
DOI: 10.1210/clinem/dgz016 -
International Dental Journal Feb 2024The aim of this research was to collate and analyse the data on the oral health knowledge and the related habits of a Hungarian cohort of monozygotic (MZ) and dizygotic...
OBJECTIVE
The aim of this research was to collate and analyse the data on the oral health knowledge and the related habits of a Hungarian cohort of monozygotic (MZ) and dizygotic (DZ) twins using the newly developed World Health Organisation Oral Health Questionnaire for Adults (Annex 7).
METHOD
A total of 15 sets of MZ twins and 14 sets of DZ twins (58 individuals) aged between 18 and 71 years were enrolled in the study. Each participant had to fill out a web-based questionnaire which comprised 23 questions (Google Forms). The data were collated and the oral health/hygiene habits of MZ and DZ twins were compared.
RESULTS
No significant differences were detected between MZ and DZ twins with regards to their daily tooth-cleaning habits or the tooth-cleaning products used by the 2 groups. For instance, when asked how often they clean their teeth, 80% of MZ twins and 71% of DZ twins responded similarly. Further, both groups provided similar responses when questioned about the use of fluoride toothpaste, frequency of dental visits, and dental counselling received as well as a number of other parameters such as snacking of sweets and fear of visiting dentists.
CONCLUSIONS
Our pilot analysis of the questionnaire responses from MZ and DZ twins in Hungary did not indicate any significant differences in their oral care habits in general. Further studies with a large cohort are required to confirm or refute our findings.
Topics: Adult; Humans; Adolescent; Young Adult; Middle Aged; Aged; Twins, Dizygotic; Pilot Projects; Hungary; Oral Health; Habits
PubMed: 37482503
DOI: 10.1016/j.identj.2023.06.012 -
Italian Journal of Pediatrics Sep 2022The majority of studies are limited to adverse perinatal outcomes and poor cognitive abilities in the short term in discordant monochorionic twins.
BACKGROUND
The majority of studies are limited to adverse perinatal outcomes and poor cognitive abilities in the short term in discordant monochorionic twins.
METHODS
To determine whether small and large discordant dizygotic twins differ in physical growth and intelligence development and weight and height from birth up to 6 years of age were measured in 34 dizygotic twin pairs with ≥ 20% birth weight discordance. Mental developmental index (MDI) and psychomotor developmental index (PDI) were calculated at 1 year, while the Wechsler Intelligence Scale for Children-IV (WISC-IV) full-scale intelligence quotient (IQ) was assessed at the age of 6.
RESULTS
The difference in height and weight in each stage differed significantly from birth to 72-months-old (P < 0.05), although there was disappointing catch-up growth in smaller twins. PDI but not MDI at 1 year of age was significantly different between the two groups (P < 0.05), and smaller twins experienced higher psychomotor retardation rates (P < 0.05). Also, the influence of height and weight on PDI was statistically significant (P < 0.05). No significant difference was detected in the WISC-IV full-scale IQ at the age of 6; however, the full-scale IQ may be affected by the history of suffocation and the S/D value (P = 0.011, P = 0.022).
CONCLUSIONS
Intrauterine fetal growth and development lead to birth weight differences in twins and sustain an impact on the children's physical growth in height and weight from birth to preschool age, causing psychomotor developmental differences at 1 year of age. However, the differences in psychomotor development decrease gradually by the age of 6.
Topics: Birth Weight; Child; Child, Preschool; Female; Humans; Intelligence; Parturition; Pregnancy; Prospective Studies; Twins, Dizygotic
PubMed: 36064427
DOI: 10.1186/s13052-022-01354-y